5 Things You Should Know About the 'New' Southern Ocean

Southern Ocean and nearby oceans
Located at the southernmost end of Earth, the Southern Ocean surrounds Antarctica like a gigantic ring. Sometimes called the Antarctic Ocean, its currents flow around the continent in enormous spirals, pushing large amounts of cold water into the other oceans. QAI Publishing/Getty Images/HowStuffWorks

It's not often we add a new geographical feature to the map of the world. For the past century, we've impressed upon our grade-schoolers that there are four major bodies of salt water on our planet: the Arctic, Atlantic, Indian and Pacific oceans. These oceans are connected to one another but divided by the world's seven continents.

But scientists have long recognized a fifth ocean, called the Southern Ocean. In 1937, the body of water surrounding Antarctica was recognized by the International Hydrographic Organization (IHO), only to be stripped of its status by the organization in 1953. In the U.S., the National Oceanic and Atmospheric Administration (NOAA) has recognized the fifth ocean since 1999, but now the international scientific community has taken the Southern Ocean public. The recognition of the world's fifth ocean, made official on June 8, which was World Oceans Day, was made to increase awareness of the need for conservation in a region where industrial fishing has all but destroyed populations of endemic fish species over the last few decades.


Here are 5 things to know about the Southern Ocean:

1. It Used to Be Part of the Pacific Ocean

Since James Cook explored the southern latitudes in the 1770s, people have disagreed about whether or how to distinguish the Southern Ocean from the other water bodies it touches. At different points in history it has been lumped in with the Indian and Atlantic oceans, but most recently the Pacific Ocean.


2. It's the Second Smallest Ocean in the World

The Southern Ocean sits at the southernmost end of our planet, hugging the coasts of Antarctica up to 60 degrees south latitude, which means it doesn't even touch the southernmost point of South America, which is way down there. Only the Arctic Ocean is smaller.


3. It's Separated From Other Oceans by Currents, Not Continents

Separating bodies of salt water from one another is a difficult task, and it's usually done with landmasses: Is there a continent between these two oceans? Great! Let's give them different names! However, the Southern Ocean is an oddball because there's no continent separating it from the Indian, Atlantic or Pacific oceans.

Instead, the waters of the Southern Ocean are kept close to the southern continent by a fast-moving current called the Antarctic Circumpolar Current (ACC), which flows west to east around Antarctica. The waters of the ACC are colder and less salty than those of its neighboring oceans.


Freediving in the Southern Ocean
A brave soul contemplates freediving in the Southern Ocean in 2016. The extreme sport gets even more dangerous given the temperatures and threat of toppling icebergs in this extraordinary setting.
Freedive Antarctica/Barcroft/ Barcroft Media via Getty Images

4. It's Home to a Unique and Fragile Ecosystem

The Southern Ocean is the only place in the world you can see the Emperor penguin (Aptenodytes forsteri), Wendell seal (Leptonychotes weddellii) and thousands of other unique organisms that live nowhere else in the world. Not only that, it is a feeding ground for animals like the humpback whale(Megaptera novaeangliae), which migrates to the Southern Ocean to eat krill each summer to fatten up before heading north again.


5. It's Time to Recognize the Southern Ocean

Though it is remote, the Southern Ocean is in need of recognition. Climate scientists have pushed for the Southern Ocean to find its way onto our maps, because it is a hot spot in the climate crisis — in 2021 alone, two of the largest icebergs ever recorded broke off the continent. Not only that, industrial fishing pressure in the area on krill and Patagonian toothfish (which you order as Chilean sea bass in restaurants) has made it even more necessary to highlight and preserve this vulnerable area of the world.